HMG-CoA reductase inhibitors

ABSTRACT

Novel 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors which are useful as antihypercholesterolemic agents and are represented by the following general structural formulae (I) or (II):    &lt;IMAGE&gt;  (I)   &lt;IMAGE&gt; (II)   wherein: n is 1 to 5; R is hydrogen or   &lt;IMAGE&gt;  R1 is hydrogen or methyl; R2 is hydrogen or methyl; and R3 is hydrogen, C1-5 alkyl or C1-5 alkyl substituted with a member of the group consisting of phenyl, dimethylamino, or acetylamino; and the dotted lines at a, b and c represent optional double bonds and pharmaceutically acceptable salts of the compounds (II) in which R3 is hydrogen are disclosed.

This is a divisional of application Ser. No. 762,736, filed Aug. 5,1985, now U.S. Pat. No. 4,668,699.

BACKGROUND OF THE INVENTION

Hypercholesterolemia is known to be one of the prime risk factors ofcardiovascular disease such as arteriosclerosis, and there is still noeffective antihypercholesterolemic agent commercially available that hasfound wide patient acceptance. The bile acid sequestrants seem to bemoderately effective but they must be consumed in large quantities, i.e.several grams at a time and they are not very palatable.

There are agents known, however, that are very activeantihypercholesterolemic agents that function by limiting cholesterolbiosynthesis by inhibiting the enzyme, HMG-CoA reductase. These agentsinclude the natural fermentation products compactin and mevinolin and avariety of semi-synthetic and totally synthetic analogs thereof. Thenaturally occurring compounds and their semi-synthetic analogs have thefollowing general structural formulae: ##STR3## wherein: R³ is hydrogen,C₁₋₅ alkyl or C₁₋₅ alkyl substituted with a member of the groupconsisting of phenyl, dimethylamino, or acetylamino;

R⁴ is ##STR4## wherein Q is ##STR5## R⁵ is H or OH: R⁶ is hydrogen ormethyl; and a, b, c, and d represent optional double bonds, especiallywhere b and d represent double bonds or a, b, c, and d are all singlebonds.

U.S. Pat. No. 4,517,373 discloses semi-synthetic hydroxy containingcompounds represented by the above general formula wherein R⁴ is##STR6##

U.S. Pat. No. 4,346,227 and U.S. Pat. No. 4,448,979 also disclosesemi-synthetic hydroxy containing compounds represented by the abovegeneral formula wherein R⁴ is ##STR7##

U.S. Pat. No. 4,376,863 discloses a fermentation product isolated aftercultivation of a microorganism belonging to the genus Aspergillus whichhas a hydroxy containing butyryloxy side chain and is represented by theabove general formula wherein R⁴ is ##STR8##

Japanese unexamined patent application No. J59-122,483-A discloses asemi-synthetic hydroxy-containing compound represented by the abovegeneral formula wherein R⁴ is ##STR9##

SUMMARY OF THE INVENTION

This invention relates to novel compounds which are HMG-CoA reductaseinhibitors and are useful as antihypercholesterolemic agents.Specifically, the compounds of this invention are semi-synthetic analogsof compactin and mevinolin and the dihydro and tetrahydro analogsthereof which possess a terminal hydroxy group or a C₂₋₆ alkanoyloxysubstituent on the terminal carbon of the 8'-ester acyl moiety.Additionally, pharmaceutical compositions of these novel compounds, asthe sole therapeutically active ingredient, and in combination with bileacid sequestrants are disclosed.

DETAILED DESCRIPTION OF THE INVENTION

The specific HMG-CoA reductase inhibitors of this invention are thecompounds represented by the following general structural formulae (I)and (II): ##STR10## wherein: n is 1 to 5;

R is hydrogen or ##STR11## R¹ is hydrogen or methyl; R² is hydrogen ormethyl; and

R³ is hydrogen, C₁₋₅ alkyl or C₁₋₅ alkyl substituted with a member ofthe group consisting of phenyl, dimethylamino, or acetylamino; and

the dotted lines at a, b and c represent optional double bonds andpharmaceutically acceptable salts of the compounds (II) in which R³ ishydrogen.

A preferred embodiment of this invention is the class of compounds ofthe formulae (I) and (II) wherein n is 1 to 3 and R² is methyl. Asub-class of these compounds is exemplified by the compounds containingone double bond at a, b or c or two double bonds, a and c, in thedecahydronaphthalene moiety.

A more preferred embodiment of this invention is the class of compoundsof the formulae (I) and (II) wherein n is 1 to 3, R² is methyl and thedotted lines at a and c representative of double bonds. Illustrative ofthis embodiment is6(R)-[2-[8(S)-(2-methyl-4-hydroxybutyryloxy)2(S),6(R)-dimethyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1-(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-oneand the corresponding ring opened dihydroxy acids.

The most preferred embodiment of this invention is the class ofcompounds of the formulae (I) and (II) wherein n is 1 to 3 and R¹ and R²are methyl and the dotted lines at a and c are representative of doublebonds. Exemplifying this embodiment are 6(R)-[2-[8(S)-(2,2-dimethyl-4-hydroxybutyryloxy)-2(S),6(R)-dimethyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one,6(R)-[2-[8(S)-(2,2-dimethyl-5-hydroxypentanoyloxy)-2(S),6(R)-dimethyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one,and6(R)-[2-[8(S)-(2,2-dimethyl-3-hydroxypropionyloxy-2(S),6(R)-dimethyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-oneand the corresponding ring opened dihydroxy acids.

Another preferred embodiment of this invention is the class of compoundsof the formula (II) wherein R³ is hydrogen or C₁₋₅ alkyl andpharmaceutically acceptable salts of the compounds of the formula (II)wherein R³ is hydrogen.

The pharmaceutically acceptable salts of this invention include thoseformed from cations such as sodium, potassium, aluminum, calcium,lithium, magnesium, zinc, and from bases such as ammonia,ethylenediamine, N-methyl-glucamine, lysine, arginine, ornithine,choline, N,N'-dibenzylethylenediamine, chloroprocaine, diethanolamine,procaine, N-benzylphenethylamine, diethylamine, piperazine,tris(hydroxymethyl)aminomethane, and tetramethylammonium hydroxide.

The compounds of formula (I) are conveniently prepared from compactin,mevinolin or the appropriate dihydro or tetrahydro analog thereof viathe following general synthetic pathway: ##STR12##

The starting materials compactin, mevinolin and their dihydro andtetrahydro analogs are readily available or may be prepared according tofermentation procedures disclosed in U.S. Pat. No. 3,983,140, U.S. Pat.No. 4,049,495, U.S. Pat. No. 4,231,938, and U.S. Pat. No. 4,294,846 andthe hydrogenation procedures disclosed in U.S. Pat. No. 4,351,844. Theappropriate starting material of formula (1) is then hydrolyzed underthe conditions disclosed in U.S. Pat. No. 4,444,784 to afford thecompounds of formula (2). The 4-hydroxy function in the lactone moietyof the compounds of formula (2) is protected with a suitable protectingagent, exemplified here as a dimethyl-t-butylsilyl group, according tothe procedure disclosed in U.S. Pat. No. 4,444,784. Acylation of the 8'hydroxy group of the compounds of the formula (3) is accomplished undersuitable conditions utilizing the appropriately substituted acid halidesof the formula (5) wherein n and R¹ are as described above, X is chloroor bromo, preferably chloro, and R' is a suitable protecting group suchas ##STR13## to afford the compounds of the formula (4). The protectinggroup at the 4-position of the lactone moiety of the compounds offormula (4) is removed utilizing suitable conditions to afford thecompounds of the formula (I) wherein R is ##STR14## To arrive at thecompounds of formula (I) wherein R is hydrogen, the R' group is removedunder suitable conditions, such as basic conditions when R¹ is a##STR15##

The appropriately substituted acid halides of the formula (5) areconveniently prepared from known starting material utilizing standardchemical transformations.

The synthesis of these compounds of the formula (5) wherein n is 2 or 3is accomplished as follows: ##STR16##

Specifically, when n is 2 dihydro-3-methyl-2(3H)furanone ordihydro-3,3-dimethyl-2(3H)furanone is treated with an alkali metalhydroxide, such as sodium hydroxide, followed by acylation with a C₂₋₆alkanoyl anhydride, such as acetic anhydride and the resultingcarboxylic acid of the formula (7) is then treated with an acidhalide-forming agent, such as oxalyl chloride, to yield the desired acidhalide of the formula (5). For the compounds of the formula (5) whereinn is 3, the analogous starting materialstetrahydro-3-methyl-2(2H)pyranone ortetrahydro-3,3-dimethyl-2(2H)pyranone are used.

The synthesis of the compounds of formula (5) wherein n is 1 is startedfrom the readily available 3-hydroxypropionic acids of the formula (6).

The compounds of the formula (II) wherein R³ is hydrogen or apharmaceutically acceptable salt thereof are readily prepared by themild basic hydrolysis of the lactone moiety of the compounds of formula(I), careful acidification and formation of the appropriate saltutilizing standard procedures.

The compounds of the formula (II) wherein R³ is C₁₋₅ alkyl or asubstituted C₁₋₅ alkyl may be conveniently prepared by the proceduresdescribed in U.S. Pat. No. 4,342,767.

The compounds of this invention are useful as antihypercholesterolemicagents for the treatment of arteriosclerosis, hyperlipidemia, familialhypercholesterolemia and the like diseases in humans. They may beadministered orally or parenterally in the form of a capsule, a tablet,an injectable preparation or the like. It is usually desirable to usethe oral route. Doses may be varied, depending on the age, severity,body weight and other conditions of human patients but daily dosage foradults is within a range of from about 2 mg to 2000 mg (preferably 2 to100 mg) which may be given in two to four divided doses. Higher dosesmay be favorably employed as required.

The compounds of this invention may also be coadministered withpharmaceutically acceptable nontoxic cationic polymers capable ofbinding bile acids in a non-reabsorbable form in the gastrointestinaltract. Examples of such polymers include cholestyramine, colestipol andpoly[methyl-(3-trimethylaminopropyl)imino-trimethylene dihalide]. Therelative amounts of the compounds of this invention and these polymersis between 1:1 and 1:15,000.

The intrinsic HMG-CoA reductase inhibition activity of the claimedcompounds is measured in the in vitro protocol described below:

The In Vitro Determination of HMG-CoA Reductase Activity in Liver andthe In Vitro Testing of Inhibitors

The procedure to measure in vitro HMG-CoA reductase activity in ratliver involves two steps and is based upon the procedure of Alberts etal:¹

1. Preparation of liver microsomal pellets.

2. Assay of the pellet for HMG-CoA reductase activity.

Preparation of Microsomal Pellet

Microsomes are prepared from livers of 150-200 g male rats (CharlesRiver) maintained for a week on ground chow containing 2.0%cholestyramine, a bile acid sequestrant. The rats are sacrificed bycervical dislocation, and the livers removed immediately and chilled onice. All subsequent operation are carried out at 0°-5° C.

Preparation of Microsomal Pellet from Rat Livers Buffer solutions

Buffer I (for homogenization)

50 mM KPO₄ pH 7.0

0.2M sucrose

2 mM DTT

Buffer I + EDTA (for washing pellet)

50 mM KPO₄ pH 7.0

0.2M sucrose

2 mM DTT

50 mM EDTA

Procedure: all operation at 4° C.

1. Animals are sacrifice. Rinse livers with ice-cold Buffer I.

2. Blot off excess liquid, weight livers.

3. Add 2 vol. of Buffer I.

4. Mince and homogenize at 1000 rpm, 10 ups and downs.

5. Centrifuge homogenate at 12,000 rpm×15 min. discard pellet

6. Centrifuge supernatant at 40K rpm×75 min.

7. Pour off supernatant.

8. Wash pellet with Buffer I+EDTA, vortex vigorously.

9. Centrifuge again at 40K rpm×75 min.

10. Aspirate off supernatant.

11. Freeze pellet at -70° C. until further purification.

Purification of HMG-CoA Reductase from Microsomal Pellet Buffer solution

Buffer A+50% glycerol

0.1M sucrose

0.05M KCl

0.04M KPO₄ pH 7.4

0.03M EDTA

0.01M DTT

50% glycerol

Buffer A

0.1M sucrose

0.05M KCl

0.04M KPO₄ pH 7.4

0.03M EDTA

0.01M DTT

Porter Buffer

0.05M KPO₄ pH 7.4

3 mM DTT

30% glycerol

1M KCl

0.03M EDTA

Buffer B

0.04M KPO₄ pH 7.4

0.03M EDTA

0.01M DTT

Procedure: all operations are carried out at room temperature

1. To each microsomal pellet 3 ml of Buffer A+50% glycerol is added.

2. Homogenize at 1000 rpm, 10 ups and downs.

3. Incubate microsomal homogenate at 37° C. for 60 minutes.

4. Add Buffer A to microsomal homogenate to bring down glycerolconcentration to 8% or less.

5. Centrifuge homogenate at 40K rmp×60 min.

6. Do 0-35% (NH₄)₂ SO₄ precipitation.

7. Centrifuge at 15K rpm×15 min. discard pellet.

8. To the supernatant, do 35-50% (NH₄)₂ SO₄ precipitation.

9. Centrifuge at 15K rpm×15 min. aspirate off supernatant.

10. To each pellet, add 1 ml Porter Buffer, mix well.

11. Do heat treatment at 65° C. for 6 minutes.

12. Centrifuge at 40K rpm×30 min. discard pellet.

13. Dilute supernatant 1:3 with Buffer A to dilute out KClconcentration.

14. Do 0-60% (NH₄)₂ SO₄ precipitation.

15. Centrifuge at 15K rpm×15 min. discard supernatant.

16. Take up pellet in least volume of Buffer A.

17. Store at -70° C.

Assay of HMG-CoA Reductase Activity

The complete assay system is in a total volume of 0.8 ml in phosphatebuffer at pH 7.2 (100 mM) with the cofactors at the followingconcentrations: MgCl₂ 3 mM; NADP, 3 mM; glucose-6-phosphate, 10 mM;glucose-6-phosphate dehydrogenase (ED 1.1.1.49) 3.0 enzyme units;reduced glutathione, 50 mM; HMG-CoA (Glutaryl-3-¹⁴ C) 0.2 mM (0.1 μCi)and enzyme suspension, 0.1 ml.

The frozen pellet (enzyme) is allowed to thaw at room temperature for 5minutes and carefully mixed with a stirring rod to a slurry with 0.1 mlof phosphate buffer (pH 7.2) and then diluted to 2.0 ml with the buffer.A volume (0.1 ml) of enzyme suspension is added to each incubation tube.Compounds to be tested are diluted to an appropriate concentration andadded in a volume to 10 μ before adding the enzyme. An"untreated-control" is run along with the compounds.

The complete system is placed in 16×125 mm screw-cap culture tubes andshaken uncapped in a 37° C. water bath for 40 minutes at 160oscillations per minute. At the end of this period the reaction isstopped by the addition of 0.4 ml of 8N HCl. 3 Mg of unlabeledmevalonolactone in 0.1 ml H₂ O is added and the tubes shaken as beforefor an additional 30 minutes at 37° C. to ensure lactonization of thebiosynthetic mevalonate.

Isolation of Product

200 μl of reaction mixture are applied to Bio-Rex 5 column (5 cm in aPasteur pipette). Elute three times with one ml each of water into ascintillation vial. Add 10 ml of Aquasol-2, shake and count.

Bio-Rex is an ion-exchange resin, obtained from Bio-Rad. It comes dry inthe chloride form and only the 100-200 mesh should be used. It isswelled in water for several hours; any fine particles should bedecanted off as these will impair the flow rate. The hydrated resinshould be stored at 4° C.

Calculation of % Inhibition

Each assay includes 2 untreated controls plus a "killed control"(reaction is stopped immediately before incubation by addition of 0.4 mlof 8N HCl).

After subtracting killed control CPM from all samples, percentinhibition by the test compounds is calculated as follows: ##EQU1##

Representative of the intrinsic HMG-CoA reductase inhibitory activitiesof the claimed compounds tabulated below are a number of claimedcompounds and the IC₅₀ values and relative potencies thereof.

    ______________________________________                                        Compounds of the Formula (II)                                                                          Relative.sup.1                                       n    R     R.sup.1  R.sup.2                                                                            R.sup.3                                                                             IC.sub.50 (μM)                                                                     Potency                                ______________________________________                                        2    H     CH.sub.3 CH.sub.3                                                                           H     0.0156  64                                     1    H     CH.sub.3 CH.sub.3                                                                           H     0.02    80                                     3    H     CH.sub.3 CH.sub.3                                                                           H     0.03    63                                     2    H     H        CH.sub.3                                                                           H     0.04    30                                     ______________________________________                                         .sup.1 Relative to compactin arbitrarily assigned a value of 100         

Included within the scope of this invention is the method of treatingarteriosclerosis, familal hypercholesterolemia or hyperlipidemia whichcomprises administering to a subject in need of such treatment anontoxic therapeutically effective amount of the compounds of formulae(I) or (II) or pharmaceutical compositions thereof.

The following examples illustrate the preparation of the compounds ofthe formulae (I) and (II) and their incorporation into pharmaceuticalcompositions and as such are not to be considered as limiting theinvention set forth in the claims appended hereto.

EXAMPLE 1 Preparation of6(R)-[2-[8(S)-(2,2-Dimethyl-4-hydroxybutyryloxy-2(S),6(R)-dimethyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one(a)6(R)-[2-[8(S)-Hydroxy-2(S),6(R)-dimethyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one(2)

A mixture of 20.0 g (49.4 mmol) of mevinolin and 20.7 g (0.493 mol) ofLiOH-H₂ O in 1.5 L of water was stirred at reflux for 72 hours. Thereaction mixture was cooled to 0° C., acidified by addition of 50 ml ofconc HCl and then extracted with ether (3×500 ml). The combined extractswere washing with water (3×500 ml) and satd. brine (500 ml), dried(MgSO₄) and evaporated to give a white solid. This solid was dissolvedin 300 ml of toluene and heated at reflux for 2 hours in a Dean-Starkapparatus for azeotropic removal of water. After evaporation of thetoluene, the residual oily solid was heated at reflux in hexane (150 ml)for 30 minutes. After cooling to 0° C., the hexane solution was filteredand the collected solid was dried in air to yield an off-white powder.An analytical sample was prepared by recrystallization of a portion ofthis material from 1 -chlorobutane to give white clusters: m.p.128°-131° C. (vac).

Anal. Cal'd for C₁₉ H₂₈ O₄.0.1C₄ H₉ Cl: C, 70.67; H, 8.84.

Found: C, 70.77; H, 8.75.

(b)6(R)-[2-[8(S)-Hydroxy-2(S),6(R)-dimethyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1(S)-ethyl]-4(R)-tert-butyldimethylsilyloxy-3,4,5,6-tetrahydro-2H-pyran-2-one

A mixture of 18.3 g (57.1 mmol) of alcohol from Example 1(a), 12.9 g(85.6 mmol) of tert-butyldimethylchlorosilane and 11.6 g (171.2 mmol) ofimidazole in 200 ml of DMF was stirred at 20° C. for 18 hours. Thereaction mixture was diluted with 1.5 L of ether and washed successivelywith water, 2% aq HCl, water and satd. aq NaHCO₃. The ether solution wasdried (MgSO₄), filtered and reduced to one liter. After addition of 600ml of hexane, the volume was reduced to 600 ml on a steam bath.Crystallization at room temperature provided the silyl ether as a white,cottony solid:

m.p. 142°-144° C. (vac).

Anal. Calcd for C₂₅ H₄₂ O₄ Si: C, 69.08; H, 9.74.

Found: C, 69.46; H, 9.83.

(c) Dihydro-3,3-dimethyl-2(3H)furanone¹

The dihydro-3-methyl-2(3H)furanone (10.0 g, 0.1 mol) was slowly added toa cold (-78° C.), THF solution (150 ml) of LDA (0.11 mol) so that theinternal temperature did not exceed -65° C. After stirring for anadditional 30 minutes, the acetone/CO₂ bath was replaced with a CH₃CN/CO₂ bath and CH₃ I (21.3 g, 0.15 mol) was added at a rate sufficientto maintain the internal temperature at -30° C. After stirring at -30°C. for another hour the reaction mixture was allowed to warm to 0° C.and quenched by the dropwise addition of 10% HCl (40 ml, 0.116 mol). Theresulting mixture was poured into ether (700 ml) and the ether layer waswashed with brine (2×50 ml), dried (MgSO₄), and evaporated to a yellowoil. The oil was distilled to give desired product as a colorlessliquid, bp₁₈ 80°-82° C.

(d) 2,2-Dimethyl-4-hydroxybutanoic acid sodium salt

A solution of 1N NaOH (89 ml, 89 mmol) and the lactone from Example 1(c)(10.0 g, 87.6 mmol) in methanol (50 ml) was stirred at ambienttemperature for 18 hours. The solution was concentrated to dryness invacuo (bath temperature 50° C.). The residue was suspended in toluene(2×50 ml) and the toluene evaporated in vacuo to provide sodium salt asa white powder.

(e) 4-Acetyloxy-2,2-dimethylbutanoic acid

A mixture of the sodium salt from Example 1(d) (5.3 g, 34.4 mmol) and4-pyrrolidinopyridine (1 g, 6.9 mmol) in pyridine (20 ml) was cooled to0° C. (ice/acetone bath). After the acetic anhydride (7.02 g, 68.8 mmol)was added, the cooling bath was removed and the reaction mixture wasstirred at ambient temperature for 18 hours. The reaction mixture wascooled to 0° C., acidified with 6N HCl, saturated with NaCl andextracted with ether (3×50 ml). The combined extracts were washed withsaturated brine (3×25 ml), dried (MgSO₄), and evaporated to give a paleyellow liquid. A NMR spectrum showed that this liquid was a mixture ofthe acid and lactone. An ether solution of the mixture was extractedwith saturated NaHCO₃ solution (4×10 ml). The combined extracts wereacidified with 6N HCl, and the resulting mixture extracted with ether(3×50 ml). The combined ether extracts were dried (MgSO₄), andevaporated to give a pale yellow oil which was distilled to provide theacid as a colorless liquid: bp₀.5 103°-104° C.

(f) 4-Acetyloxy-2,2-dimethylbutyrylchloride

A solution of the acid from Example 1(e) (14.0 g, 80.4 mmol), oxalylchloride (11.2 g, 88.4 mmol) and DMF (4 drops) in benzene (50 ml) wasstirred at ambient temperature for 1 hour. The light red solution wasdistilled to provide the acid chloride as a colorless liquid: bp₀.572°-74° C.

(g)6(R)-[2-[8(S)-(4-Acetyloxy-2,2-dimethylbutyryloxy)-2(S),6(R)-dimethyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1(S)]ethyl]-4(R)-tert-butyldimethylsilyloxy-3,4,5,6-tetahydro-2H-pyran-2-one

A stirred solution of the alcohol from Example 1(b) (8.9 g, 20.5 mmol),4-pyrrolidinopyridine (610 mg, 4.1 mmol) and the acid chloride fromExample 1(f) (3.9 g, 20.5 mmol) in pyridine (50 ml) was heated under anitrogen atmosphere at 100° C. After 2 hours, 4 hours and 10 hours,another 1.95 g of the acid chloride was added and the reaction solutionwas stirred for a total of 18 hours. After cooling to 60° C., thepyridine was removed (in vacuo) and the residue was diluted with ether(500 ml). The resulting mixture was wahsed with 1N HCl (2×25 ml), satd.NaHCO₃ solution (25 ml), satd. brine (2×50 ml) and dried (MgSO₄).Evaporation of the ether solution gave the crude produce as a yellowliquid. This liquid was chromatographed on a 17.5×7 cm column of silicagel (230-400 mesh). Elution (under air pressure) with acetone-methylenechloride (1:99, v:v) provided the ester contaminated with acid and acidchloride which was used in the next step without further purification.

(h)6(R)-[2-[8(S)-(4-Acetyloxy-2,2-dimethylbutyryloxy)-2(S),6(R)-dimethyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one

A solution of the crude ester from Example 1(g) (12.3 g, 20.8 mmol) inTHF (100 ml) was treated with acetic acid (4.7 ml, 83.2 mmol) and a 1Msolution of tetrabutylammonium fluoride in THF (62.4 ml, 62.4 mmol) andwas stirred at ambient temperature for 20 hours. The reaction mixturewas diluted with ether (500 ml) washed with 1.5N HCl (50 ml), satd.NaHCO (50 ml) and satd. brine (2×50 ml) and dried (MgSO₄). The solventwas evaporated to provide a pale yellow oil which was used in the nextstep without further purification.

(i)6(R)-[2-[8(S)-(2,2-Dimethyl-4-hydroxybutyryloxy)-2(S),6(R)-dimethyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one

A solution of the crude lactone from Example 1(h) 10.1 g, 21.8 mmol) and10N NaOH (5.45 ml, 54.5 mmol) in methanol (100 ml) was stirred atambient temperature for 2 hours. The solution was evaporated in vacuoand the residue was cooled (ice/water bath) and acidified with 3N HCland extracted with ether (3×200 ml). The combined extracts were washedwith satd. brine (2×25 ml), dried (MgSO₄) and evaporated to give aviscous tan oil. The oil was dissolved in toluene (300 ml) and heated atreflux for 3 hours in a Dean-Stark apparatus in order to relactonize thedihydroxy acid. The toluene was removed in vacuo and the crude lactonewas chromatographed on a 18×7 cm column of silica gel (230-400 mesh).Elution (under air pressure) with acetone-methylene chloride (7:13; v:v)provided the lactone as a colorless solid. The solid was recrystallizedfrom ether/hexane to provide the title compound. m.p. 124°-126° C.

TLC Data: R_(f) 0.28 [MK 6F silica gel, acetonemethylene chloride (7:13;v:v)].

Anal. Calc'd for C₂₅ H₃₈ O₆ : C, 69.09; H, 8.81.

Found: C, 68.99; H, 8.58.

EXAMPLE 2 Preparation of 6(R)-[2-[8(S)-(2methyl-4-hydroxybutyryloxy)-2(S),6(R)-dimethyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one(a) 2-Methyl-4-hydroxybutanoic acid sodium salt

Employing the procedure of Example 1(d) but usingdihydro-3-methyl-2(3H)furanone (30 g, 0.3 mol) the title compound wasobtained as a white solid and was used without further purification inthe following step. NMR (D₂ O) δ 1.10 (3H, d, J=7 H), 1.37-2.00 (2 H,m), 2.18-2.57 (H, m), 3.60 (2H, t, J=7 Hz).

(b) 4-Acetoxy-2-methylbutanoic acid

Employing the procedure of Example 1(e) but using compound from Example2(a) (38.7 g, 0.276 mol) the title compound was obtained as a paleyellow liquid. b.p.₀.1 102°-105° C., NMR (CDCl₃) δ 1.23 (3 H, d, J=7Hz), 1.60-2.27 (2 H, m), 2.02 (3 H, s), 2.43-2.50 (H, m), 4.10 (2 H, t,J=7 Hz).

(c) 4-Acetoxy-2-methylbutyryl chloride

Employing the procedure of Example 1(f), but using the compound fromExample 2(b) (9.2 g, .057 mol), the title compound was obtained as acolorless liquid, b.p.₀.3 60°-61° C.

NMR (CDCl₃) δ 1.33 (3 H, d, J=7 Hz), 1.63-2.40 (2 H, m), 2.03 (3 H, s),2.77-3.20 (H, m), 4.13 (2H, +, J=7 Hz).

(d)6(R)-[2-[8(S)-(2-methyl-4-hydroxybutyryloxy)-2(S),6(R)-dimethyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one

Employ the general procedures in Example 1(g) through 1(i), the compoundfrom Example 2(c) was converted into the title compound, m.p. 124°-8° C.

Anal. Calcd. for C₂₄ H₃₆ O₆ : C, 68.54; H, 8.63.

Found: C, 68.57; H, 8.97.

EXAMPLE 3 Preparation of6(R)-[2-(8(S)-(2,2-dimethyl-3-hydroxypropionoyloxy)-2(S),6(R)-dimethyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one(a) 3-Acetoxy-2,2-dimethylpropionic acid

Acetyl chloride (4.52, 58.2 mmol) was added dropwise to a cold (0° C.)pyridine solution (10 ml) of 2,2-dimethyl-3-hydroxypropionic acid (5.5g, 46.5 mmol) and 4-DMAP (0.57 g, 4.65 mmol). After stirring overnightat ambient temperature, the reaction was poured into ether (200 ml).This mixture was washed with 10% HCl (2×20 ml), and saturated brine(2×25 ml) and the resulting ethereal solution was dried (MgSO₄).Evaporation gave the title compound as a pale yellow solid which wasused in the next step without further purification. NMR (CDCl₃) δ 4.13(2 H, s), 2.08 (3 H, s), 1.26 (6 H, s).

(b) 3-Acetoxy-2,2-dimethylpropionyl chloride

A benzene solution (25 ml) of crude 3-acetoxy-2,2-dimethyl proprionicacid from Example 3(a) (7.4 g, 46.5 mmol), oxalyl chloride (6.45 g, 51ml) and DMF (2 drops) was stirred at ambient temperature for 3 hours.The pale yellow solution was distilled to provide the title compound asa colorless liquid, b.p.₁₅ 85°-88° C. NMR (CDCl₃) δ 4.18 (2 H, s), 2.08(3 H, s), 1.35 (6 H, s).

(c) 6(R)-[2-(8(S)-(2,2-dimethyl-3-hydropropionyloxy)-2(S),6(R)-dimethyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one

Employing the general procedures in Example 1(g) through 1(i), thecompound from Example 3(b) was converted into the title compound. m.p.162°-5° C.

Anal. Calcd. for C₂₄ H₃₆ O₆ : C, 68.54; H, 8.63.

Found: C, 68.41; H, 8.76.

EXAMPLE 4 Preparation of6(R)-[2-[8(S)-(2,2-dimethyl-5-hydroxypentanoyloxy)-2(S),6(R)-dimethyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one(a) 3-Methyltetrahydro-2H-pyran-2-one

Tetrahydro-2H-pyran-2-one (10.0 g, 0.10 mol) was slowly added to a cold(-78° C.) THF solution (100 ml) of LDA (0.11 mol) so that the internaltemperature did not exceed -65° C. After stirring for an additional 30minutes, the acetone/CO₂ bath was removed and CH₃ I (21.3 g, 0.15 mol)was added dropwise. When the internal temperature reached -30° C. thereaction was placed in a CH₃ CN/CO₂ bath to maintain the internaltemperature at -35°±5° C. After stirring for 1 hour, the reactionmixture was allowed to warm to 0° C. and was quenched by the dropwiseaddition of sat. NH₄ Cl solution. The resulting mixture was poured intoether (300 ml) and the ether layer was separated and washed with H₂ O(50 ml), 1 N HCl (25 ml), saturated brine (2×50 ml), dried (MgSO₄) andevaporated to provide an orange oil. Distillation of the oil gave thetitle compound as colorless oil. b.p.₁₅ 103°-105° C. NMR (CDCl₃) δ 4.32(2 H, m), 2.58 (H, m), 2.08 (H, m), 1.84 (2 H, m), 1.52 (H, m), 1.26 (3H, d, J=7Hz).

(b) 3,3-Dimethyltetrahydro-2H-pyran-2-one

The 3-methyltetrahydro-2H-pyran-2-one from Example 4(a) (5.6 g, 49.0mmol) was slowly added to a cold (-78° C.) THF solution (50 ml) of LDA(54 mmol) so that the internal temperature did not exceed -65° C. Afterstirring for an additional 30 minutes, the acetone/CO₂ bath was replacedwith a CH₃ CN/CO₂ bath and CH₃ I (10.4 g, 73.5 mmol) was added at a ratesufficient to maintain the internal temperature at -45° C. Afterstirring at -45° C. for an additional hour the reaction was allowed towarm to -30° C. and quenched by the dropwise addition of 10% HCl (21ml). The resulting mixture was poured into ether (300 ml) and the etherlayer was washed with saturated brine (50 ml), saturated NaHCO₃ solution(20 ml), saturated brine (2×25 ml), dried (MgSO₄) and evaporated toprovide a pale yellow oil. This oil was distilled to give the titlecompound as a colorless liquid. b.p.₀.2 54° C. NMR (CDCl₃) δ 4.34 (2 H,m), 1.89 (2 H, m), 1.75 (2 H, m), 1.30 (6H, s).

(c) 2,2-Dimethyl-5-hydroxypentanoic acid sodium salt

Employing the procedure of Example 1(d), but using the compound fromExample 4(b) (5.0 g, 39 mmol), the title compound was obtained as awhite solid and was used without further purification in the followingstep. NMR (D₂ O) δ 3.57 (2 H, m), 1.47 (4 H, m), 1.10 (6 H, s).

(d) 5-Acetyloxy-2,2-dimethylpentanoic acid

Employing the procedure of Example 1(e), but using the compound fromExample 4(c) (6.5 g, 38.6 mmol), the title compound was obtained as acolorless liquid. b.p.₀.2 120°-124° C. NMR (CDCl₃) δ 4.06 (2 H, m), 2.06(3 H, s), 1.62 (4 H, m), 1.22 (6 H, s).

(e) 5-Acetyloxy-2,2-dimethylpentanoyl chloride

Employing the procedure of Example 1(f), but using the compound fromExample 4(d) (2.4 g, 12.7 mmol), the title compound was obtained as acolorless liquid. b.p.₀.2 72°-74° C. NMR (CDCl₃) δ 4.06 (2H, m), 2.06 (3H, s), 1.68 (4 H, m), 1.31 (6 H, s).

(f) 6(R)-[2-[8(S)-(2,2-dimethyl-5-hydroxypentanoyloxy)-2(S),6(R)-dimethyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1-(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one

Employing the general procedures in Example 1(g) through 1(i), thecompound from Example 4(e) was converted into the title compound. m.p.90°-93° C.

Anal. Calcd. for C₂₆ H₄₀ O₆ 0.1 CH₂ Cl₂ : C, 68.58; H, 8.87.

Found: C, 68.63; H, 9.00.

EXAMPLES 5 to 15

Utilizing the general procedures of Examples 1 to 4 the followingcompounds of the formula (I) in the following table are prepared fromthe appropriate acid chloride and compactin, mevinolin, and the dihydroand tetrahydro analogs thereof.

    ______________________________________                                        Compound                                                                              n       R        R.sup.1                                                                             R.sup.2                                                                            a     b   c                               ______________________________________                                        5       5       H        CH.sub.3                                                                            CH.sub.3                                                                           db    --  db                              6       2       H        CH.sub.3                                                                            H    db    --  db                              7       3       H        CH.sub.3                                                                            CH.sub.3                                                                           --    db  --                              8       2       H        CH.sub.3                                                                            CH.sub.3                                                                           db    --  --                              9       1       H        CH.sub.3                                                                            CH.sub.3                                                                           --    --  db                              10      2       H        CH.sub.3                                                                            CH.sub.3                                                                           --    --  --                              11      2       CH.sub.3 CO                                                                            CH.sub.3                                                                            H    db    --  db                              12      1       C.sub.3 H.sub.7 CO                                                                     H     H    --    --  --                              13      5       H        CH.sub.3                                                                            H    --    db  --                              14      1       H        H     H    db    --  db                              15      3       H        CH.sub.3                                                                            H    db    --  db                              ______________________________________                                         db = double bond                                                         

EXAMPLE 16 Preparation of7-[1,2,6,7,8,8a(R)-Hexahydro-2(S),6(R)-dimethyl-8(S)-(2,2-dimethyl-4-hydroxybutyryloxy)naphthalenyl-1(S)]-3(R),5(R)-dihydroxyheptanoicacid, ammonium salt

The lactone from Example 1(i) (434 mg, 1 mmol) was dissolved withstirring in 0.1N NaOH (1.1 mmol) at r.t. The resulting solution wascooled to 0° C. and acidified by the dropwise addition of 1N HCl. Theresulting mixture was extracted with ether (2×50 ml) and the etherextracts were combined, washed with brine (3×25 ml) and dried (MgSO₄).The MgSO₄ was removed by filtration and the filtrate saturated withammonia (gas) to give a gum which solidified to provide the ammoniumsalt; m.p. eff. 160°-162° C. The solid (100 mg) can be recrystallized bydissolution in warm CH₃ CN/conc. NH₄ OH (4:1; v:v, 4 ml) followed bydilution with CH₃ CN to give colorless needles; m.p. eff. 160°-162° C.

TLC Data: R_(f) 0.22 [MK 6F silica gel, acetic acid-methylene chloride(3:7; v:v)].

Anal. Calc'd for C₂₅ H₄₃ NO₇ : C, 63.92; H, 9.23; N, 2.98.

Found: C, 63.77; H, 9.40; N, 3.26.

EXAMPLE 17 Preparation of Alkali and Alkaline Earth Salts of Compound II

To a solution of 42 mg of the lactone from Example 1(i) in 2 ml ofethanol is added 1 ml of aqueous NaOH (10⁻⁴ moles; 1 equivalent). Afterone hour at room temperature,the mixture is taken to dryness in vacuo toyield the sodium salt of Compound II.

In like manner the potassium salt is prepared using one equivalent ofpotassium hydroxide, and the calcium salt using one equivalent of CaO.

EXAMPLE 18 Preparation of Ethylenediamine Salt of Compound II

To a solution of 0.50 g of the ammonium salt of Compound II from Example16 in 10 ml of methanol is added 75 μl of ethylenediamine. The methanolis stripped off under vacuum to obtain the ethylenediamine salt ofCompound II.

EXAMPLE 19 Preparation of Tris(hydroxymethyl)aminomethane Salt ofCompound

To a solution of 202 mg of the ammonium salt of Compound II from Example16 in 5 ml of methanol is added a solution of 60.5 mg oftris(hydroxymethyl) aminomethane in 5 ml of methanol. The solvent isremoved in vacuo to afford the desired tris(hydroxymethyl)aminomethanesalt of Compound II is filtered off and dried.

EXAMPLE 20 Preparation of L-Lysine Salt of Compound II

A solution of 0.001 mole of L-lysine and 0.0011 mole of the ammoniumsalt of Compound II from Example 16 in 15 ml of 85% ethanol isconcentrated to dryness in vacuo to give the L-lysine salt of CompoundII.

Similarly prepared are the L-arginine, L-ornithine, andN-methylglucamine salts of Compound II.

EXAMPLE 21 Preparation of Tetramethylammonium Salt of Compound II

A mixture of 68 mg of Compound II from Example 16 in 2 ml of methylenechloride and 0.08 ml of 24% tetramethylammonium hydroxide in methanol isdiluted with ether to yield the tetramethylammonium salt of Compound II.

EXAMPLE 22 Preparation of Methyl Ester of Compound II

To a solution of 400 mg of the lactone from Example 1(i) in 100 ml ofabsolute methanol is added 10 ml 0.1M sodium methoxide in absolutemethanol. This solution is allowed to stand at room temperature for onehour, is then diluted with water and extracted twice with ethyl acetate;the ethyl acetate, dried over anhydrous sodium sulfate, is removed invacuo to yield the methyl ester of Compound II.

In like manner, by the use of equivalent amounts of propanol, butanol,isobutanol, t-butanol, amylalcohol, isoamylalcohol,2-dimethylaminoethanol, benzylalcohol, phenethanol, 2-acetamidoethanol,and the like, the corresponding esters are obtained.

EXAMPLE 23 Preparation of free Hydroxy Acids

The sodium salt of the compound II from Example 17 is redissolved in 2ml of ethanol-water (1:1) and added to 10 ml of 1N hydrochloric acidfrom which the hydroxy acid is extracted with ethyl acetate. The lattersolvent is washed once with water, dried, and removed in vacuo with abath temperature not exceeding 30° C. The hydroxy acid derived slowlyreverts to the lactone on standing.

EXAMPLE 24

As a specific embodiment of a composition of this invention, 20 mg ofthe lactone from Example 1(i) is formulated with sufficient finelydivided lactose to provide a total amount of 580 to 590 mg to fill asize 0 hard gelatin capsule.

What is claimed is:
 1. A compound represented by the following generalstructural formula (II): ##STR17## wherein: n is 1 to 5;R is hydrogen;R¹ is methyl; R² is hydrogen or methyl; and R³ is hydrogen, C₁₋₅ alkylor C₁₋₅ alkyl substituted with a member of the group consisting ofphenyl, dimethylamino, or acetylamino; and the dotted lines at a, b andc represent optional double bonds or a pharmaceutically acceptable saltof the compound (II) in which R³ is hydrogen.
 2. A compound of claim 1wherein n is 1 to 3 and R² is methyl.
 3. A compound of claim 2 whereinone of the dotted lines at a, b or c represents a double bond or thedotted lines at a and c represent double bond.
 4. A compound of claim 3wherein the dotted lines at a and c represent double bonds.
 5. Acompound of claim 4 which is7-[1,2,6,7,8,8a(R)-hexahydro-2(S),6,(R)-dimethyl-8(S)-(2,2-dimethyl-4-hydroxybutyryloxy)-naphthalenyl-1(S)]-3(R),5(R)-dihydroxyheptanoicacid.
 6. A compound of claim 4 which is7-[1,2,6,7,8,8a(R)-hexahydro-2(S),6(R)-dimethyl-8(S)-(2,2-dimethyl-5-hydroxypentanoyloxy)naphthalenyl-1(S)]-3(R),5(R)-dihydroxyheptanoicacid.
 7. A compound of claim 4 which is7[1,2,6,7,8,8a(R)-hexahydro-2(S),6(R)-dimethyl-8(S)-(2,2-dimethyl-3-hydroxypropionyloxy)naphthalenyl-1(S)]-3(R),5(R)-dihydroxyheptanoicacid.
 8. A hypocholesterolemic, hypolipidemic pharmaceutical compositioncomprising a nontoxic therapeutically effective amount of a compound ofclaim 1 and a pharmaceutically acceptable carrier.
 9. A pharmaceuticalcomposition of claim 8 wherein the therapeutically active ingredient isselected from:(1)7-[1,2,6,7,8,8a(R)-hexahydro-2(S),6(R)-dimethyl-8(S)-(2,2-dimethyl-4-hydroxybutyryloxy)-naphthalenyl-1(S)]-3,(R),5(R)-dihydroxyheptanoicacid; (2)7-[1,2,6,7,8,8a(R)-hexahydro-2(S),6(R)-dimethyl-8(S)-(2,2-dimethyl-5-hydroxypentanoyloxy)-naphthalenyl-1(S)]-3,(R),5(R)-dihydroxyheptanoicacid; and (3)7-[1,2,6,7,8,8a(R)-hexahydro-2(S),6(R)-dimethyl-8(S)-(2,2-dimethyl-3-hydroxypropionyloxy)-naphthalenyl-1(S)]-3,(R),5(R)-dihydroxyheptanoicacid.
 10. A method of inhibiting cholesterol biosynthesis comprising theadministration to a subject in need of such treatment a nontoxictherapeutically effective amount of a compound of claim
 1. 11. A methodof claim 10 wherein the therapeutically active ingredient is selectedfrom:(1)7-[1,2,6,7,8,8a(R)-hexahydro-2(S),6(R)-dimethyl-8(S)-(2,2-dimethyl-4-hydroxybutyryloxy)-naphthalenyl-1(S)]-3(R),5(R)-dihydroxyheptanoicacid; (2)7-[1,2,6,7,8,8a(R)-hexahydro-2(S),6(R)-dimethyl-8(S)-(2,2-dimethyl-5-hydroxypentanoyloxy)-napththalenyl-1(S)]-3(R),5(R)-dihydroxyheptanoicacid; and (3)7-[1,2,6,7,8,8a(R)-hexahydro-2(S),6(R)-dimethyl-8(S)-(2,2-dimethyl-3-hydroxypropionyloxy)-naphthalenyl-1-(S)]-3(R),5(R)-dihydroxyheptanoicacid.